Arab Board Dermatology Final flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Auspitz sign

Pinpoint bleeding that occurs when scale is removed from a psoriatic plaque, reflecting dilated capillaries in the elongated dermal papillae.

Koebner phenomenon

Development of new lesions at sites of trauma or injury, classically seen in psoriasis, lichen planus, and vitiligo.

Wickham striae

Fine white lacy lines on the surface of lichen planus papules and on mucosal lesions, representing hypergranulosis.

PASI score

Psoriasis Area and Severity Index; combines erythema, induration, and desquamation weighted by body surface area, ranging from 0 to 72.

Langerhans cells

CD1a-positive, langerin-positive dendritic antigen-presenting cells in the epidermis that migrate to lymph nodes to initiate T-cell responses.

Filaggrin

Protein that aggregates keratin filaments in the stratum corneum; loss-of-function mutations cause ichthyosis vulgaris and predispose to atopic dermatitis.

Desmoglein 3

Cadherin adhesion protein in desmosomes; autoantibodies against it cause pemphigus vulgaris with mucosal and cutaneous flaccid blisters.

BP180

Transmembrane hemidesmosome protein (collagen XVII); autoantibodies against it cause bullous pemphigoid with tense subepidermal blisters.

Heliotrope rash

Violaceous erythema of the upper eyelids, a characteristic cutaneous sign of dermatomyositis often accompanied by periorbital edema.

Gottron papules

Erythematous to violaceous papules over the knuckles and interphalangeal joints, a pathognomonic sign of dermatomyositis.

Chicken-wire immunofluorescence

Intercellular IgG deposition in the epidermis on direct immunofluorescence, characteristic of pemphigus vulgaris.

Wood's lamp

Ultraviolet light source (365 nm) used to examine skin; Microsporum species fluoresce blue-green in tinea capitis, and vitiligo appears bright white.

Honey-colored crust

Golden-yellow crust typical of non-bullous impetigo, caused by Staphylococcus aureus or Streptococcus pyogenes.

Burrow

Linear, thread-like tunnel in the stratum corneum created by the scabies mite, often found in web spaces and wrists.

Molluscum bodies

Large eosinophilic intracytoplasmic inclusions (Henderson–Paterson bodies) seen in keratinocytes infected by molluscum contagiosum poxvirus.

Breslow thickness

Depth of melanoma invasion measured from the granular layer to the deepest tumor cell; the strongest prognostic factor for survival.

Peripheral palisading

Arrangement of basaloid cells in a row at the periphery of tumor islands, a histologic feature of basal cell carcinoma.

Pautrier microabscess

Cluster of atypical lymphocytes within the epidermis, characteristic of mycosis fungoides.

Leser–Trélat sign

Sudden eruption of multiple seborrheic keratoses, sometimes associated with underlying malignancy, especially gastrointestinal adenocarcinoma.

Ash-leaf spot

Hypopigmented, leaf-shaped macule on the trunk or limbs, a major diagnostic criterion for tuberous sclerosis.

Kawasaki disease

Febrile vasculitis of childhood with conjunctivitis, mucositis, rash, extremity changes, and cervical adenopathy; risk of coronary aneurysms; treated with IVIG and aspirin.

Incontinentia pigmenti

X-linked dominant genodermatosis (IKBKG mutation) with vesicular, verrucous, hyperpigmented, and hypopigmented stages along Blaschko lines; lethal in males.

Propranolol

Beta-blocker used as first-line therapy for problematic infantile hemangiomas; reduces proliferation and accelerates involution.

Mohs micrographic surgery

Staged excision with complete margin examination of frozen sections; spares normal tissue and has high cure rates for high-risk skin cancers.

Pulsed dye laser

Vascular laser (595 nm) targeting oxyhemoglobin; used for port-wine stains and telangiectasias; may cause purpura and pigmentary changes.

Exclamation-mark hairs

Short broken hairs with a tapered proximal end and wider distal end, seen at the periphery of alopecia areata patches.

Hutchinson sign

Pigment extending onto the cuticle or proximal nail fold in longitudinal melanonychia, suggesting subungual melanoma.

Telogen effluvium

Diffuse, self-limited hair shedding occurring 2–3 months after a physiologic stressor, due to premature transition of follicles into telogen.

SPF

Sun protection factor; ratio of UVB dose needed to produce erythema on protected versus unprotected skin; does not directly measure UVA protection.

Porphyria cutanea tarda

Disorder of uroporphyrinogen decarboxylase causing blistering, fragility, and hypertrichosis on sun-exposed skin; associated with hepatitis C and alcohol.

Isotretinoin teratogenicity

Retinoid that causes severe birth defects; requires pregnancy testing and two contraceptive methods before and during treatment.

DRESS syndrome

Drug reaction with eosinophilia and systemic symptoms; fever, rash, lymphadenopathy, and organ involvement; treated with systemic corticosteroids.